The invention relates to an electrohydraulic servomechanism for adjusting a desired value that is a mutual angular position of a threaded spindle relative to a tap by a stepper motor.
From German Pat. No. 2,062,134 a servomechanism is known in which the thread of a spindle is developed as a standard thread. The reproducibility of the adjustment is achieved by friction and by altering conditions of the oil film upon controlling the threaded spindle at 400 steps per rotation. With this principle, however, the reproducibility of the position of a working element is not very accurate.